Sustanon 250 or Sustamed Sustandrol (a trading name owned by Balkan Pharmaceuticals) is a blend of four esterified testosterone compounds:
- 30 mg testosterone propionate
- 60 mg testosterone phenylpropionate
- 60 mg testosterone isocaproate
- 100 mg testosterone decanoate
The numbers in the names refer to the fact that the content of testosterone compounds in each blend are 250 and 100 mg/ml, respectively.
The different testosterone esters provide for different half-lives. Esterization of the testosterone molecules provides for a sustained (but non-linear) release of testosterone hormone from the injection depot into the blood plasma.
While the intention of the mixed testosterone esters in Sustanon is to provide more stable serum testosterone levels, single long-ester testosterone, such as testosterone cypionate or testosterone enanthate, may actually provide more stable serum testosterone levels